Lawyers in the manslaughter trial of a Weymouth man charged with killing his father last year told jurors on Tuesday to expect to hear heart-wrenching evidence of a strained family relationship that ended in bloodshed.

DEDHAM – Lawyers in the manslaughter trial of a Weymouth man charged with killing his father last year told jurors on Tuesday to expect to hear heart-wrenching evidence of a strained family relationship that ended in bloodshed.

Prosecutor Lisa Beatty told a Norfolk Superior Court jury that Michael Beaudry, now 22, fatally struck 58-year-old Ronald Beaudry in the head with a piece of hard plastic pipe after an argument spilled into the road outside their Cross Street home.

Michael Beaudry is charged with manslaughter in connection with his father’s death on Feb. 4, 2013, and assault and battery stemming from a separate alleged assault against his father the previous September.

But Beaudry’s attorney Jack Atwood, of Plymouth, said Ronald Beaudry was the aggressor in an increasingly hostile relationship with his son and that Michael Beaudry’s actions were “reasonable and justified,” when he swung the pipe at his father.

Atwood said that jurors would hear evidence that Ronald Beaudry has been drinking alcohol prior to both altercations with his son.

At his district court arraignment in February 2013, prosecutors said Michael Beaudry had argued with his father over a BB gun before leaving the house carrying a 3-foot piece of PVC pipe and a small propane tank he planned to use to build a rocket at a friend’s house. When his father followed him into the street, Beaudry allegedly hit him with the pipe and knocked him to the ground.

When police arrived, they found Michael Beaudry holding a shirt against his father’s bleeding head and pleading with officers and bystanders to save his father, according to police. Ronald Beaudry was taken to South Shore Hospital and died a short time later.

Michael Beaudry is a 2011 graduate of Weymouth High School. Ronald Beaudry grew up in Hyde Park and served in the Air Force during the Vietnam War, according to his obituary. He lived in Weymouth for 31 years and was an active member of American Legion Post 79. He worked for 25 years as a steam fireman at Quincy Medical Center.

Michael Beaudry was initially charged with murder and pleaded not guilty at his arraignment in Quincy District Court. A Norfolk County grand jury indicted him on the lesser charge of manslaughter.

Christian Schiavone may be reached at cschiavone@ledger.com or follow him on Twitter @CSchiavo_Ledger.